Nice use of colour. We have a preference for example: #18 as it'll work better in site navigation. This darker blue works well compared to the aqua of other designs. I'd like to see some more work on the figure... perhaps it could become a bit more abstract and iconographic?
Nice work - I especially like example: #30. You can almost see a G in the design as well, which is nice. I wonder if you could change the font to something similar to example: #6, and if you could try a red version as well as the blue one. Very promising - well done!